To prevent flush water or filth from being spilt out of a gap between an attachable and detachable bucket and a housing in a toilet unit installed in a room or the like.

On the lower surface of a tank 1, a flush water nozzle 3 is provided to be protruded forwards, the attitude of a bucket 7 is inclined by installing a supporting plate 6 to have a downward gradient backwards from a front end thereof, and a comparatively wide gap is positively formed between the lower surface of an upper surface portion 4a of the housing and the back side upper edge of the bucket 7 so that the interference of the nozzle 3 and the bucket 7 can be avoided. Stability in the case of mounting the bucket is improved as well. A screen cover 10 for overlaying the gap has a pendant part 12 which hangs downwards, and the front end side portion of the pendant part 12 is formed into tapered shape sharpened forwards. The flush water emitted from the nozzle or filth in the case of excretion can be prevented by the screen cover 10 from being split around, and the mounting work of the bucket is facilitated by sharpening the front end side area of the pendant part.